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EP0108871A1 - Method and device for monitoring and/or controlling the welding current in the high frequency resistance pressure welding of pipes with a straight bead - Google Patents

Method and device for monitoring and/or controlling the welding current in the high frequency resistance pressure welding of pipes with a straight bead Download PDF

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Publication number
EP0108871A1
EP0108871A1 EP83108134A EP83108134A EP0108871A1 EP 0108871 A1 EP0108871 A1 EP 0108871A1 EP 83108134 A EP83108134 A EP 83108134A EP 83108134 A EP83108134 A EP 83108134A EP 0108871 A1 EP0108871 A1 EP 0108871A1
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EP
European Patent Office
Prior art keywords
welding
welding current
magnetic field
probe
current
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP83108134A
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German (de)
French (fr)
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EP0108871B1 (en
Inventor
Wilfried Dipl.-Ing. Kliesch
Friedrich-Otto Dipl.-Ing. Koch
Hans-Jürgen Dipl.-Phys. Wahl
Rolf Dipl.-Ing. Krebs
Peter Dipl.-Ing. Schorr
Heinz Strauch
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Hoesch AG
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Hoesch Werke AG
Hoesch AG
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Priority to AT83108134T priority Critical patent/ATE23685T1/en
Publication of EP0108871A1 publication Critical patent/EP0108871A1/en
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Publication of EP0108871B1 publication Critical patent/EP0108871B1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K13/00—Welding by high-frequency current heating
    • B23K13/01—Welding by high-frequency current heating by induction heating
    • B23K13/02—Seam welding
    • B23K13/025—Seam welding for tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K13/00—Welding by high-frequency current heating
    • B23K13/01—Welding by high-frequency current heating by induction heating
    • B23K13/02—Seam welding

Definitions

  • the invention relates to a method according to the preamble of claim 1.
  • the invention is based on US-PS 35 73 416, from which it is known to detect the welding currents in the HF welding of longitudinal seam pipes behind the welding point from the outside by magnetic measurement. Similar solutions to problems e.g. DE-OS 19 25 965.
  • the object of the invention is therefore to propose an uncomplicated method for monitoring and / or regulating the welding current, in which disturbing influences from adjacent magnetic fields are largely eliminated.
  • the probes are expediently arranged in the middle of the path between the current feed point (induction coil or RF contacts) and the welding point (the strip edges of the slotted tube meet between the compression rollers) directly below the strip edges in the magnetic field of the strip edge welding currents.
  • a disturbance due to pipe back currents is generally not noticeable there. If necessary, you can also measure the pipe back currents by means of sensors sensitive to magnetic fields inside the pipe and draw conclusions about the remaining welding currents in the strip edges.
  • the probes are arranged on the support arm for the slotted tube sword or the scraper device for the internal welding bead.
  • the probes should expediently be attached to the surface of the impedance to be used.
  • the impeder is wrapped with an induction loop and this is coupled to a display or signaling device for the operator so that the current induced in the loop can be monitored. Damage or destruction of the Impeders can be discovered immediately.
  • a change in the magnetic field is proportional to the change in the welding current in the strip edges.
  • this measuring method can be used practically as a temperature measuring method.
  • a slotted tube 1 is pressure welded to the longitudinal seam tube at the welding point 6.
  • the welding pressure is applied via compression rollers 7, 8.
  • the welding energy is conductively introduced into the slotted tube 1 by a welding generator (not shown) via the contact shoes 13, 14 and flows due to the skin effect as a welding current 15 in the strip edges 4, 5 to the welding point 6 and as a back current 16 around the slotted tube 1 .
  • an induction coil 2 or 3 is arranged as a magnetic field-sensitive probe between the contact shoes 13 and 14 and the welding point 6 near the band edges 4 and 5 in the interior of the slotted tube 1.
  • the leads lo of the induction coils 2, 3 are guided separately from the slotted tube 1, so that the voltage induced in each induction coil 2, 3 can be evaluated independently via a measuring device 11 and a recorder 12.
  • Fig. 2 shows an enlarged version of the formation of the opposite magnetic fields, which are generated by the welding current 15 in the strip edges 4 and 5 of the slotted tube 1.
  • the induction coil 2 on the support arm 9 measures the magnetic field at the strip edge 4, the induction coil 3 the magnetic field at the strip edge 5.
  • the current distribution on the strip edges 4 and 5 can thus be detected independently of one another. E.g. due to scaling of the tube surface changes in resistance between slotted tube 1 and contact shoe 13 or 14 on one side or on both sides, this is registered.
  • the measuring device 11 contains limit switches for maximum and minimum voltages, i.e. proportional maximum. and minimal. Welding currents 15. If the values abruptly exceed or fall below e.g. by short circuit, a signal is given to a marking device, not shown, for the accurate marking of the fault location.
  • the change in voltage ie change in welding current
  • the probe can be used for corresponding control signals for readjusting the welding generator with the aim of maintaining constant welding currents 15.
  • the invention can also be carried out if the probe is located on the outside of the tube. In such a case, the probe or coil would have to be very flat and be covered by a shielding plate.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
  • Arc Welding Control (AREA)

Abstract

Bei der HF-Schweißung von Längsnahtrohren ist zur Beherrschung des Schweißprozeßes eine möglichst genaue Erfassung der Schweißtemperatur erforderlich. Die Schweißtemperaturänderungen erfolgen proportional zu Änderungen des in den Bandkanten (4, 5) eines Schlitzrohres (1) fließenden Schweißstromes (15). Über magnetfeldempfindliche Sonden (2, 3) sollen Schweißstromänderungen und somit Temperaturänderungen direkt und genau erfaßt werden. Somit soll einerseits eine Verarbeitung der in den Sonden (2, 3) induzierten Spannungen zu Stellsignalen für die Nachregelung des HF-Schweißgenerators möglich und anderseits eine Schweißstromstörung über entsprechende Signale für ein Markiergerät am Rohr ortgetreu markierbar sein, damit dieses Rohrstück später aussortiert werden kann.When HF welding longitudinal seam tubes, the welding temperature must be recorded as precisely as possible in order to master the welding process. The changes in welding temperature are proportional to changes in the welding current (15) flowing in the strip edges (4, 5) of a slotted tube (1). Magnetic field sensitive probes (2, 3) are used to directly and precisely record changes in welding current and thus changes in temperature. Thus, on the one hand, the voltages induced in the probes (2, 3) should be processed to control signals for the readjustment of the HF welding generator and, on the other hand, a welding current disturbance should be able to be marked on the pipe by appropriate signals for a marking device, so that this pipe section can be sorted out later.

Description

Die Erfindung betrifft ein Verfahren gemäß dem Oberbegriff des Anspruches 1.The invention relates to a method according to the preamble of claim 1.

Die Erfindung geht aus von der US-PS 35 73 416, aus der bekannt ist, die Schweißströme bei der HF-Schweißung von Längsnahtrohren hinter dem Schweißpunkt von außen durch magnetische Messung zu erfassen. Gleichartige Problemlösungen liefert z.B. die DE-OS 19 25 965.The invention is based on US-PS 35 73 416, from which it is known to detect the welding currents in the HF welding of longitudinal seam pipes behind the welding point from the outside by magnetic measurement. Similar solutions to problems e.g. DE-OS 19 25 965.

Diese Verfahren haben den Nachteil, daß bei der Messung die Magnetfelder der zur Schweißvorrichtung führenden Stromkabel, die sich bei den üblichen Schweißfrequenzen von etwa 4oo kHz nur unzureichend abschirmen lassen, stören. Gleiches gilt für Magnetfelder von in der näheren Umgebung eingesetzten Induktiv-Glühanlagen wie z.B. Nahtnachglühanlagen für Rohre. Als besonders störend für die nur interessierende Erfassung des in den Bandkanten für den eigentlichen Erhitzungsvorgang fließenden Stromes erweisen sich die bei der konduktiven und stärker noch bei der induktiven Stromeinkopplung in das Rohr entstehenden sogenannten Rohr-Rückenströme.These methods have the disadvantage that the magnetic fields of the power cables leading to the welding device, which cannot be adequately shielded at the usual welding frequencies of about 4oo kHz, interfere with the measurement. The same applies to magnetic fields from inductive annealing systems used in the vicinity, e.g. Seam afterglow systems for pipes. The so-called pipe back currents that arise during the conductive and even more so during the inductive coupling of current into the pipe prove to be particularly disturbing for the only interesting detection of the current flowing in the strip edges for the actual heating process.

Aus der DE-OS 28 26 986 ist eine sehr spezifische Art der Erfassung von Schweißphänomenen und deren Weiterverarbeitung für die Schweißenergieregelung bekannt.From DE-OS 28 26 986 a very specific type of detection of welding phenomena and their further processing for welding energy control is known.

Diese Vorrichtung ist jedoch außerordentlich aufwendig.However, this device is extremely complex.

Von daher hat die Erfindung die Aufgabe, ein umkompliziertes Verfahren für die 0berwachung und/oder Regelung des Schweißstromes vorzuschlagen, bei dem störende Einflüsse benachbarter Magnetfelder weitestgehend ausgeschaltet sind.The object of the invention is therefore to propose an uncomplicated method for monitoring and / or regulating the welding current, in which disturbing influences from adjacent magnetic fields are largely eliminated.

Die Aufgabe wird erfindungsgemäß durch die im Kennzeichen des Anspruches 1 erfaßten Merkmale gelöst. Weiterbildende Merkmale sind in den Unteransprüchen erfaßt.The object is achieved by the features recorded in the characterizing part of claim 1. Further features are covered in the subclaims.

Effektiv wirksam für den Schweißprozeß ist nur der in den Bandkanten des Schlitzrohres fließende Schweißstrom. Aus diesem Grunde wird nur über ihn eine Aussage gewünscht, insbesondere, ob und wann er Schwankungen unterliegt. Diese werden dann zur Nachfolgeregelung der eingespeisten Schweißenergie verwertet.Only the welding current flowing in the strip edges of the slotted tube is effective for the welding process. For this reason, only a statement about him is desired, especially whether and when he is subject to fluctuations. These are then used for the subsequent regulation of the welding energy fed in.

Dies gelingt insbesondere durch Anbringen einer magnetfeldempfindlichen Sonde im Rohrinneren. Der Vorteil der Magnetfeldmessung im Rohrinneren besteht darin, daß das Rohr für die hohen Frequenzen des Schweißgenerators einen Faradaykäfig bildet. Hierdurch werden alle elektromagnetischen Störfelder, die sich außerhalb des Rohres befinden, abgeschirmt. Ebenso können infolge des Skineffektes, alle auf der äußeren Rohroberfläche fließenden Ströme nicht nach innen dringen, abgesehen von dem in den Bandkanten des Schweißspaltes fließenden Strömen, die für den HF-Preßschweißprozeß entscheidend sind. Somit kann man also auf der Rohrinnenseite fast störungsfrei die Magnetfelder des Schweißstromes messen.This is achieved in particular by attaching a magnetic field sensitive probe inside the pipe. The advantage of measuring the magnetic field inside the tube is that the tube forms a Faraday cage for the high frequencies of the welding generator. This shields all electromagnetic interference fields that are outside the pipe. Likewise, due to the skin effect, all the currents flowing on the outer pipe surface cannot penetrate inwards, apart from the currents flowing in the strip edges of the welding gap, which are decisive for the HF pressure welding process. This means that the magnetic fields of the welding current can be measured almost without interference on the inside of the pipe.

Dabei ergibt sich noch der Vorteil, daß man durch Anbringen mehrerer auf das Magnetfeld der Schweißströme ausgerichteter Induktionsspulen als Sonden differenziertere Aussagen über den Schweißprozeß, speziell über die Verteilung der Ströme im Rohr machen kann. Hinzu kommt als weiterer Vorteil, daß man beliebig kurze Schweißstromstörungen, wie sie z.B. infolge Kurzschlusses durch Späne denkbar sind, erfassen kann, was bei herkömmlichen Meßmethoden nicht möglich ist. Solche kurzen Störungen können zwar nicht ausgeregelt werden, da auch der Regelkreis eine gewisse Trägheit hat, sie können jedoch mittels einer Markiereinrichtung ortsgetreu markiert oder durch Abspeichern in ein Schieberegister registriert und verfolgt oder aufgezeichnet werden.There is also the advantage that, by attaching several induction coils aligned as a probe to the magnetic field of the welding currents, one can make more differentiated statements about the welding process, especially about the distribution of the currents in the tube. In addition, there is a further advantage that one can have welding current disturbances of any length, such as are conceivable, for example, as a result of a short circuit due to chips are able to record what is not possible with conventional measuring methods. Such short disturbances cannot be corrected because the control loop also has a certain inertia, but they can be marked with the help of a marking device or recorded and tracked or recorded by storing them in a shift register.

Die Sonden werden zweckmäßigerweise in der Mitte der Strecke zwischen Stromeinspeisepunkt (Induktionsspule oder HF-Kontakte) und Schweißpunkt (Zusammentreffen der Bandkanten des Schlitzrohres zwischen den Stauchrollen) direkt unter den Bandkanten im Magnetfeld der Bandkanten-Schweißströme angeordnet. Dort ist eine Störung durch Rohr-Rückenströme in der Regel nicht wahrnehmbar. Falls erforderlich kann man auch noch die Rohr-Rückenströme durch magnetfeldempfindliche Sonden im Rohrinneren erfassen und auf die verbleibenden Schweißströme in den Bandkanten schließen.The probes are expediently arranged in the middle of the path between the current feed point (induction coil or RF contacts) and the welding point (the strip edges of the slotted tube meet between the compression rollers) directly below the strip edges in the magnetic field of the strip edge welding currents. A disturbance due to pipe back currents is generally not noticeable there. If necessary, you can also measure the pipe back currents by means of sensors sensitive to magnetic fields inside the pipe and draw conclusions about the remaining welding currents in the strip edges.

Bei der konduktiven HF-Schweißung werden die Sonden auf dem Trägerarm für das Schlitzrohr-Schwert bzw. die Schabeeinrichtung für den Innenschweißwulst angeordnet.In the case of conductive HF welding, the probes are arranged on the support arm for the slotted tube sword or the scraper device for the internal welding bead.

Im Falle der induktiven HF-Schweißung sollten die Sonden zweckmäßigerweise auf der Oberfläche des einzusetzenden Impeders angebracht sein. Um Funktionsstörungen durch beschädigte Impeder auszuschalten, wird in Weiterbildung des Erfindungsgedankens der Impeder mit einer Induktionsschleife umwickelt und diese mit einer Anzeige- oder Meldevorrichtung für den Bedienungsmann gekoppelt, so daß der in die Schleife induzierte Strom überwacht werden kann. Beschädigungen oder Zerstörungen des Impeders können so sofort entdeckt werden.In the case of inductive HF welding, the probes should expediently be attached to the surface of the impedance to be used. In order to eliminate malfunctions due to damaged impeders, in further development of the inventive idea the impeder is wrapped with an induction loop and this is coupled to a display or signaling device for the operator so that the current induced in the loop can be monitored. Damage or destruction of the Impeders can be discovered immediately.

Eine Irreführung der magnetfeldempfindlichen Sonde durch diese Störung kann somit vermieden werden.Misleading of the magnetic field sensitive probe by this disturbance can thus be avoided.

Eine Änderung des Magnetfeldes erfolgt proportional zur Änderung des Schweißstromes in den Bandkanten.A change in the magnetic field is proportional to the change in the welding current in the strip edges.

Da eine Schweißstromänderung eine proportionale Temperaturänderung beim Schweißen zur Folge hat, ist dieses Meßverfahren praktisch als Temperaturmeßverfahren anwendbar.Since a change in welding current results in a proportional change in temperature during welding, this measuring method can be used practically as a temperature measuring method.

Hier liegt die hervorragende Bedeutung für die Anwendung bei der HF-Rohrschweißtechnik, da alle bisher verwendeten Temperaturmeßverfahren über Strahlungspyrometer wegen der Umwelt-Bedingungen am Schweißpunkt nicht die für eine optimale Schweißung erforderliche Genauigkeit aufweisen.This is of outstanding importance for the application in HF tube welding technology, since all temperature measurement methods used up to now using radiation pyrometers do not have the accuracy required for optimal welding due to the environmental conditions at the welding point.

Anhand einiger schematischer Zeichnungen soll ein Ausführungsbeispiel näher erläutert werden.An exemplary embodiment will be explained in more detail with the aid of a few schematic drawings.

Es zeigen

  • Fig. 1 die Situation an der HF-Schweißstation bei der Verschweißung der Bandkanten des Schlitzrohres zum Längsnahtrohr
  • Fig. 2 einen Teilschnitt quer zum Schlitzrohr in Höhe der Magnetfeld-Sonden
Show it
  • Fig. 1 shows the situation at the HF welding station during the welding of the band edges of the slotted tube to the longitudinal seam tube
  • Fig. 2 shows a partial section transverse to the slotted tube at the level of the magnetic field probes

Ein Schlitzrohr 1 wird im Schweißpunkt 6 zum Längsnahtrohr preßgeschweißt. Der Schweißdruck wird über Stauchrollen 7, 8 aufgebracht. (Fig. 1) Die Schweißenergie wird von einem nicht dargestellten Schweißgenerator über die Kontaktschuhe 13, 14 konduktiv in das Schlitzrohr 1 eingeleitet und fließt infolge des Skineffektes als Schweißstrom 15 in den Bandkanten 4, 5 zum Schweißpunkt 6 und als Rückenstrom 16 um das Schlitzrohr 1.A slotted tube 1 is pressure welded to the longitudinal seam tube at the welding point 6. The welding pressure is applied via compression rollers 7, 8. (Fig. 1) The welding energy is conductively introduced into the slotted tube 1 by a welding generator (not shown) via the contact shoes 13, 14 and flows due to the skin effect as a welding current 15 in the strip edges 4, 5 to the welding point 6 and as a back current 16 around the slotted tube 1 .

Auf dem Trägerarm 9 ist zwischen den Kontaktschuhen 13 bzw. 14 und dem Schweißpunkt 6 nahe unter den Bandkanten 4 bzw. 5 im Inneren des Schlitzrohres 1 je eine Induktionsspule 2 bzw. 3 als magnetfeldempfindliche Sonde angeordnet. Die Zuleitungen lo der Induktionsspulen 2, 3 werden getrennt aus dem Schlitzrohr 1 geführt, so daß man die in jeder Induktionsspule 2, 3 induzierte Spannung unabhängig über ein Meßgerät 11 und einen Schreiber 12 auswerten kann.On the support arm 9, an induction coil 2 or 3 is arranged as a magnetic field-sensitive probe between the contact shoes 13 and 14 and the welding point 6 near the band edges 4 and 5 in the interior of the slotted tube 1. The leads lo of the induction coils 2, 3 are guided separately from the slotted tube 1, so that the voltage induced in each induction coil 2, 3 can be evaluated independently via a measuring device 11 and a recorder 12.

Fig. 2 zeigt in vergrößerter Ausführung die Ausbildung der entgegengesetzten Magnetfelder, die durch den Schweißstrom 15 in den Bandkanten 4 bzw. 5 des Schlitzrohres 1 erzeugt werden. Die Induktionsspule 2 auf dem Trägerarm 9 mißt das Magnetfeld an der Bandkante 4, die Induktionsspule 3 das Magnetfeld an der Bandkante 5. Die Stromverteilung auf die Bandkanten 4 und 5 kann also unabhängig voneinander erfaßt werden. Treten z.B. infolge Verzunderung der Rohroberfläche Widerstandsänderungen zwischen Schlitzrohr 1 und Kontaktschuh 13 bzw. 14 einseitig oder beidseitig auf, wird diese registriert.Fig. 2 shows an enlarged version of the formation of the opposite magnetic fields, which are generated by the welding current 15 in the strip edges 4 and 5 of the slotted tube 1. The induction coil 2 on the support arm 9 measures the magnetic field at the strip edge 4, the induction coil 3 the magnetic field at the strip edge 5. The current distribution on the strip edges 4 and 5 can thus be detected independently of one another. E.g. due to scaling of the tube surface changes in resistance between slotted tube 1 and contact shoe 13 or 14 on one side or on both sides, this is registered.

Das Meßgerät 11 enthält Grenzwertgeber für maximale und minimale Spannungen, d.h. proportionale maximale. und minimale. Schweißströme 15. Bei abruptem Ober- oder Unterschreiten der Werte z.B. durch Kurzschluß wird ein Signal an eine nicht dargestellte Markiereinrichtung zur ortsgetreuen Markierung der Störstelle gegeben.The measuring device 11 contains limit switches for maximum and minimum voltages, i.e. proportional maximum. and minimal. Welding currents 15. If the values abruptly exceed or fall below e.g. by short circuit, a signal is given to a marking device, not shown, for the accurate marking of the fault location.

Ansonsten kann die Spannungsänderung, d.h. Schweißstromänderung für entsprechende Stellsignale zur Nachregelung des Schweißgenerators genutzt werden mit dem Ziel, konstante Schweißströme 15 zu erhalten. Die Erfindung ist auch ausführbar, wenn die Sonde an der Außenseite des Rohres sitzt. In einem solchen Fall müßte die Sonde oder Spule sehr flach gebaut sein und von einem Abschirmblech überdeckt sein.Otherwise, the change in voltage, ie change in welding current, can be used for corresponding control signals for readjusting the welding generator with the aim of maintaining constant welding currents 15. The invention can also be carried out if the probe is located on the outside of the tube. In such a case, the probe or coil would have to be very flat and be covered by a shielding plate.

Claims (13)

1. Verfahren zur Überwachung und/oder Regelung des Schweißstromes bei der HF-Schweißung von Längsnahtrohren durch Erfassung der durch den Schweißstrom erzeugten Magnetfelder mittels einer Sonde, dadurch gekennzeichnet, daß die Magnetfelder der Schweißströme in den Bandkanten von der Sonde erfaßt und in eine Spannung umgesetzt werden und die Spannungsschwankungen überwacht und mit vorgegebenen Sollwerten für die Schwankungsbreite verglichen werden und bei Überschreitung der Sollwerte zur Nachregelung des Schweißstromes ein Stellsignal geformt wird und/oder eine Markiervorrichtung betätigt wird.1. A method for monitoring and / or regulating the welding current in the HF welding of longitudinal seam pipes by detecting the magnetic fields generated by the welding current by means of a probe, characterized in that the magnetic fields of the welding currents in the strip edges are detected by the probe and converted into a voltage are monitored and the voltage fluctuations are monitored and compared with predetermined target values for the fluctuation range and if the target values for readjustment of the welding current are exceeded, an actuating signal is formed and / or a marking device is actuated. 2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das Magnetfeld von der Rohrinnenseite her erfaßt wird.2. The method according to claim 1, characterized in that the magnetic field is detected from the inside of the tube. 3. Verfahren nach den Ansprüchen 1 und 2, dadurch gekennzeichnet, daß beiden Bandkanten je eine Sonde zugeordnet wird.3. The method according to claims 1 and 2, characterized in that each band edge is assigned a probe. 4. Verfahren nach den Ansprüchen 1 - 3, dadurch gekennzeichnet, daß die Sonden zwischen dem Stromeinspeisepunkt und dem Schweißpunkt, vorzugsweise in der Mitte dieser Strecke, angeordnet werden.4. The method according to claims 1-3, characterized in that the probes are arranged between the current feed point and the welding point, preferably in the middle of this distance. 5. Verfahren nach den Ansprüchen 3 und 4, dadurch gekennzeichnet, daß Abweichungen der erfaßten Magnetfeldstärken zwischen den Sonden in Spannungssignale umgesetzt und diese zur Regelung des Schweißstromes genutzt werden.5. The method according to claims 3 and 4, characterized in that deviations of the detected magnetic field strengths between the probes are converted into voltage signals and these are used to regulate the welding current. 6. Verfahren nach den Ansprüchen 1 - 5, dadurch gekennzeichnet, daß eine Induktionsspule als Sonde verwendet wird.6. The method according to claims 1-5, characterized in that an induction coil is used as a probe. 7. Verfahren nach den Ansprüchen 1 - 6, dadurch gekennzeichnet, daß die erfaßten Magnetfeldschwankungen registriert und/oder gespeichert werden.7. The method according to claims 1-6, characterized in that the detected magnetic field fluctuations are registered and / or stored. 8. Verfahren nach den Ansprüchen 1 - 7, dadurch gekennzeichnet, daß über einen vorgegebenen Sollwert hinausgehende punktuell erfaßte Magnetfeldschwankungen durch Sondensignale an eine Markiereinrichtung zur ortsgetreuen Markierung des Rohres gemeldet werden.8. The method according to claims 1-7, characterized in that over and above a predetermined target value point-detected magnetic field fluctuations are reported by probe signals to a marking device for accurate marking of the tube. 9. Verfahren nach den Ansprüchen 1 - 8, dadurch gekennzeichnet, daß bei der induktiven HF-Schweißung die Sonden in einen im Rohrinneren angeordneten Impeder integriert werden und der Impeder mit einer Induktionsspule zur Überwachung der Impederfunktion umwickelt wird.9. The method according to claims 1-8, characterized in that in the inductive HF welding, the probes are integrated in an arranged inside the tube Impeder and the Impeder is wrapped with an induction coil for monitoring the Impederfunction. 10. Verfahren nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß zusätzlich der Rohr-Rückenstrom von der Rohrinnenseite her gemessen und mit der gesamten eingebrachten Schweißenergie verglichen wird.10. The method according to one or more of the preceding claims, characterized in that in addition the pipe backflow is measured from the inside of the pipe and compared with the total welding energy introduced. 11. Vorrichtung zur Durchführung des Verfahrens nach den Ansprüchen 1 bis 7 mit einem Hochfrequenz-Schweißgenerator und konduktiver oder induktiver Stromübertragungsvorrichtung und einem Schweißstromsteller gekennzeichnet durch zwei magnetfeldempfindliche im Rohrinneren unmittelbar vor dem Schweißpunkt unter den Bandkanten angeordnete Sonden, einem mit diesen verbundenen Maßgerät mit integrierten Grenzwertgebern, sowie einem Soll-Istwert-Vergleicher die zusammengeschaltet sind mit einer mit dem Schweißstromsteller verbundenen Regeleinrichtung.11. An apparatus for performing the method according to claims 1 to 7 with a high-frequency welding generator and a conductive or inductive current transmission device and a welding current regulator characterized by two magnetic field-sensitive probes arranged in the interior of the tube directly in front of the welding point under the strip edges, a measuring device connected to them with integrated limit sensors , and a setpoint-actual value comparator which are connected together with a control device connected to the welding current controller. 12. Vorrichtung nach Anspruch 11 zur Durchführung des Verfahrens nach Anspruch 8 gekennzeichnet durch eine mit dem Soll-Istwert-Vergleicher gekoppelten Fehlstellenmarkiereinrichtung für das Rohr.12. The device according to claim 11 for performing the method according to claim 8, characterized by a coupled with the target-actual value comparator flaw marking device for the pipe. 13. Vorrichtung nach den Ansprüchen 11 und 12 zur Durchführung des Verfahrens nach Anspruch 9 gekennzeichnet durch eine in den Impeder integrierte Sonde und eine den Impeder zusätzlich umschließende Induktionsspule.13. Device according to claims 11 and 12 for carrying out the method according to claim 9, characterized by a probe integrated in the impeder and an induction coil additionally enclosing the impeder.
EP83108134A 1982-10-20 1983-08-17 Method and device for monitoring and/or controlling the welding current in the high frequency resistance pressure welding of pipes with a straight bead Expired EP0108871B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT83108134T ATE23685T1 (en) 1982-10-20 1983-08-17 METHOD AND DEVICE FOR MONITORING AND/OR ADJUSTING THE WELDING CURRENT DURING HIGH FREQUENCY RESISTANCE PRESS WELDING OF LONG SEAM TUBES.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3238766 1982-10-20
DE19823238766 DE3238766A1 (en) 1982-10-20 1982-10-20 METHOD AND DEVICE FOR MONITORING AND / OR REGULATING THE WELDING CURRENT IN HIGH-FREQUENCY RESISTANT PRESSURE WELDING OF LENGTH SEW TUBES

Publications (2)

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EP0108871A1 true EP0108871A1 (en) 1984-05-23
EP0108871B1 EP0108871B1 (en) 1986-11-20

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EP83108134A Expired EP0108871B1 (en) 1982-10-20 1983-08-17 Method and device for monitoring and/or controlling the welding current in the high frequency resistance pressure welding of pipes with a straight bead

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US (1) US4621176A (en)
EP (1) EP0108871B1 (en)
AT (1) ATE23685T1 (en)
DE (2) DE3238766A1 (en)

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AU582619B2 (en) * 1984-12-06 1989-04-06 Nippon Steel Corporation Apparatus for automatically controlling heat input by a high-frequency power supply for welding
EP0658068A2 (en) * 1993-12-08 1995-06-14 Tocco, Inc. Device for monitoring induction coils
CN109877497A (en) * 2019-04-18 2019-06-14 燕山大学 A device and process for welding ERW pipe with mobile cooling magnet bar

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US5889262A (en) * 1997-05-15 1999-03-30 Seah Steel Corporation System for and method of automatically controlling amount of input heat in high-frequency electric resistance welding machine
KR20010058301A (en) * 1999-12-27 2001-07-05 이구택 High frequency electric resistance welding and apparatus for preventing penetrator defect
US6455825B1 (en) 2000-11-21 2002-09-24 Sandia Corporation Use of miniature magnetic sensors for real-time control of the induction heating process
AT507774B1 (en) * 2009-05-14 2010-08-15 Fronius Int Gmbh METHOD AND DEVICE FOR DETERMINING THE VOLTAGE ON THE ELECTRODES OF A POINT WELDING TONGUE
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CN102430868A (en) * 2011-10-25 2012-05-02 王建军 Hidden seam welding method for PTFE plates
CN106312386B (en) * 2016-09-21 2018-12-07 燕山大学 A kind of high-frequency straight seam welded pipe steel-pipe welding temperature online Detection & Controling experimental provision
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CN109877497A (en) * 2019-04-18 2019-06-14 燕山大学 A device and process for welding ERW pipe with mobile cooling magnet bar
CN109877497B (en) * 2019-04-18 2020-01-07 燕山大学 A device and process for welding ERW pipe with mobile cooling magnet bar

Also Published As

Publication number Publication date
DE3367747D1 (en) 1987-01-08
US4621176A (en) 1986-11-04
DE3238766A1 (en) 1984-04-26
ATE23685T1 (en) 1986-12-15
EP0108871B1 (en) 1986-11-20

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